I know several people that drink egg whites, none of them seem to have any problems of biotin deficiency, but I also don’t think they’ve been doing it consistently for a long enough time maybe....so I only know what I know based on what I’ve read, but there are many studies that seem to confirm that it might cause a problem....plus you lose a pretty big portion of the protein from the eggs if they aren’t cooked...
Again, this is all coming from studies I’ve read, not personal experience, but even the possibility of it being legit was enough to turn me away from it lol.
So now I eat a whole tub of fat free cottage cheese every day instead...not quite as simple as drinking egg whites, plus I hate cottage cheese, but it’s still a cheap and easy way to get 90 grams of protein per day without having to cook or mix anything